Please refer to FIG. 1, there is shown a schematic diagram of the circuit of a wireless transceiver in accordance with the prior art. The circuit 10 of the wireless transceiver comprises a transceiver chip 12 and an antenna. The transceiver chip 12 comprises a transmitter circuit 121 and a receiver circuit 123. The transceiver pad 129 is switched to connect to the transmitter circuit 121 or the receiver circuit 123 by the switch 125. To filter the image signal out, a notch filter 16 comprising an inductor 161 and a capacitor 163 is needed in the circuit 10.
If the notch filter 16 is disposed in the transceiver chip 12, the cost to produce the transceiver chip 12 is increased. On the other hand, if the notch filter 16 is disposed on the circuit board (not shown), the cost is increased for the device producer.
Furthermore, for preventing the elements of the transceiver chip 12 from being damaged by the current of electrostatic discharge, an electrostatic discharge (ESD) protection circuit 127 is connected between the transceiver pad 129 and the ground pad 128 in the transceiver chip 12.
However, the transceiver pad 129 is on the signal path for signal receiving and transmitting. The parasitic capacitance or parasitic inductance between the ESD protection circuit 127 and the signal path degrades the performance of the transceiver chip 12.